running rich again !! 92 lt1
11-25-2004, 01:44 AM
#1
Racer
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Location: Jonesboro AR
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running rich again !! 92 lt1
my 92 just had a bad exhaust leak. the left manifold botts came off.
anyway i fixed it and now it is running very very rich again. it is stumbling at anyting under 1000 rpm.
i tried disconnecting the batter to let the ecm reset itself. then drove it 25 miles or so and nothing yet.
the only other thing i think it might be is i also adjusted the screw on the throtle body about a full turn - i did this to raise my idle temporarly. could that cause it to run rich?
anyway i fixed it and now it is running very very rich again. it is stumbling at anyting under 1000 rpm.
i tried disconnecting the batter to let the ecm reset itself. then drove it 25 miles or so and nothing yet.
the only other thing i think it might be is i also adjusted the screw on the throtle body about a full turn - i did this to raise my idle temporarly. could that cause it to run rich?
11-25-2004, 02:58 AM
#2
Safety Car
You blew it big time!!
I think you have the L98?
Now you have to put a wire between A-B on the diag center engine stone cold.
With wire conected turn on Ign and disconect the IAC at the throttle body,with the key still on engine NOT running
pull wire from A-B terminal and start engine,you will have to try and keep it running try not to let it stall or you may have to do this again.
Engine Idle screw should be set at 450 in gear auto and 400 std trans.
Let engine run until at operating temp.
After you get that right, then go to next step.
set TPS TO .54 VOLTS AND YOU SHOULD BE SET.
I don't write to well so I will be on line for a while if you need more info.
I think you have the L98?
Now you have to put a wire between A-B on the diag center engine stone cold.
With wire conected turn on Ign and disconect the IAC at the throttle body,with the key still on engine NOT running
pull wire from A-B terminal and start engine,you will have to try and keep it running try not to let it stall or you may have to do this again.
Engine Idle screw should be set at 450 in gear auto and 400 std trans.
Let engine run until at operating temp.
After you get that right, then go to next step.
set TPS TO .54 VOLTS AND YOU SHOULD BE SET.
I don't write to well so I will be on line for a while if you need more info.
Last edited by REDC4CORVETTE; 11-25-2004 at 03:02 AM.
11-25-2004, 03:51 AM
#3
Team Owner
He has an LT1.
Rich implies the O2 sensors are asking for more fuel, or, you have an injector problem.
The IAC won't effect richness, it just sets the idle.
what I would do is check for codes...
but if you remove and clean the throttle body, that will help eliminate that as a problem source.
Resetting the IAC on an LT1 is rather easy, really. The settings listed above are correct. Remove the connector to the IAC and then turn on the key. This will set the computer into the test mode. turn off the key, reconnect, start, holding the gas pedal at about 1000 rpm. that will instruct the ECM to set the IAC.
Hold this for 5 to 10 seconds.
turn off the engine, restart, life should be perfect.
I will double check my Helms manual in the morning, but I am pretty sure this is correct.
Rich implies the O2 sensors are asking for more fuel, or, you have an injector problem.
The IAC won't effect richness, it just sets the idle.
what I would do is check for codes...
but if you remove and clean the throttle body, that will help eliminate that as a problem source.
Resetting the IAC on an LT1 is rather easy, really. The settings listed above are correct. Remove the connector to the IAC and then turn on the key. This will set the computer into the test mode. turn off the key, reconnect, start, holding the gas pedal at about 1000 rpm. that will instruct the ECM to set the IAC.
Hold this for 5 to 10 seconds.
turn off the engine, restart, life should be perfect.
I will double check my Helms manual in the morning, but I am pretty sure this is correct.
11-25-2004, 10:36 AM
#5
Racer
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Member Since: Jul 2004
Location: Jonesboro AR
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ok im retarted- what is an IAC.
the car is acting the same way as it was when i had the bad exaust leak. This makes me think its an o2 problem. However fixing the exaust should have fixed it.
the car is acting the same way as it was when i had the bad exaust leak. This makes me think its an o2 problem. However fixing the exaust should have fixed it.
11-25-2004, 01:28 PM
#7
Safety Car
Originally Posted by reed62783
ok im retarted- what is an IAC.
the car is acting the same way as it was when i had the bad exaust leak. This makes me think its an o2 problem. However fixing the exaust should have fixed it.
the car is acting the same way as it was when i had the bad exaust leak. This makes me think its an o2 problem. However fixing the exaust should have fixed it.
IAC= idle air control. If you don't have a Helms manual, now is the time to get one. The IAC is located on the bottom of the throttle body, pass. side. How many miles on the car? If the 2 O2 sensors are original to the car, its time to change them.
